libssh2: Unchecked use of _libssh2_packet_require and _libssh2_packet_requirev resulting in out-of-bounds read
Published Mar 20, 2019
9.1
CRITICALCVSS 3.1
EPSS 6.28%
Description
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the _libssh2_packet_require and _libssh2_packet_requirev functions. A remote attacker who compromises a SSH server may be able to cause a Denial of Service or read data in the client memory.
Affected products
-
- Version 1.8.1StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| The libssh2 Project | Libssh2 | n/a |
|
Configuration 2
- 28
- 29
Configuration 3
- 8.0
- 9.0
Configuration 4
- n/a
No data.
Red Hat Enterprise Linux 6
libssh2
Will not fix
Red Hat Enterprise Linux 7
libssh2
Will not fix
Red Hat Enterprise Linux 8
virt:rhel/libssh2
Will not fix
Red Hat Enterprise Linux 8 Advanced Virtualization
virt:8.0.0/libssh2
Not affected
Red Hat Virtualization 4
redhat-virtualization-host
Will not fix
Red Hat Virtualization 4
rhvm-appliance
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | libssh2 | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | libssh2 | Will not fix | n/a |
| Red Hat Enterprise Linux 8 | virt:rhel/libssh2 | Will not fix | n/a |
| Red Hat Enterprise Linux 8 Advanced Virtualization | virt:8.0.0/libssh2 | Not affected | n/a |
| Red Hat Virtualization 4 | redhat-virtualization-host | Will not fix | n/a |
| Red Hat Virtualization 4 | rhvm-appliance | Will not fix | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This flaw was present in libssh2 packages included in Red Hat Virtualization Hypervisor and Management Appliance, however libssh2 in these hosts is never exposed to malicious clients or servers.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
1 other source (Red Hat) ▾
CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L
AV:N/AC:L/Au:N/C:P/I:N/A:P
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Dec 18, 2025 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Table of values (23 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 6.28% (0.06275) | 93.38th | v5 (v2026.06.15) |
| Jun 15, 2026 | 6.28% (0.06275) | 92.66th | v5 (v2026.06.15) |
| Nov 21, 2025 | 1.03% (0.01028) | 76.64th | v4 (v2025.03.14) |
| Nov 18, 2025 | 2.83% (0.02833) | 84.92th | v4 (v2025.03.14) |
| Mar 30, 2025 | 1.05% (0.01054) | 75.58th | v4 (v2025.03.14) |
| Mar 29, 2025 | 3.15% (0.03150) | 78.06th | v4 (v2025.03.14) |
| Mar 17, 2025 | 1.08% (0.01083) | 76.33th | v4 (v2025.03.14) |
| Jan 2, 2025 | 3.65% (0.03645) | 91.58th | v3 (v2023.03.01) |
| Dec 17, 2024 | 2.60% (0.02604) | 89.99th | v3 (v2023.03.01) |
| Dec 12, 2024 | 1.52% (0.01515) | 87.52th | v3 (v2023.03.01) |
| Oct 13, 2024 | 1.80% (0.01799) | 88.44th | v3 (v2023.03.01) |
| Jul 19, 2024 | 2.91% (0.02912) | 90.92th | v3 (v2023.03.01) |
| Mar 13, 2024 | 2.07% (0.02074) | 88.79th | v3 (v2023.03.01) |
| Nov 8, 2023 | 1.26% (0.01263) | 84.06th | v3 (v2023.03.01) |
| Sep 3, 2023 | 1.18% (0.01180) | 83.30th | v3 (v2023.03.01) |
| Mar 7, 2023 | 1.34% (0.01343) | 84.00th | v3 (v2023.03.01) |
| Mar 6, 2023 | 4.36% (0.04358) | 88.02th | v2 (v2022.01.01) |
| Apr 1, 2022 | 4.36% (0.04358) | 86.83th | v2 (v2022.01.01) |
| Feb 4, 2022 | 37.15% (0.37149) | 97.07th | v2 (v2022.01.01) |
| Feb 3, 2022 | 23.90% (0.23899) | 95.04th | v1 |
| Jan 6, 2022 | 23.90% (0.23899) | 94.98th | v1 |
| Jan 5, 2022 | 6.54% (0.06542) | 90.55th | v5 (v2026.06.15) |
| Apr 14, 2021 | 6.54% (0.06542) | 0.00th | v1 |
References (24)
- http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00040.html vendor-advisoryx_refsource_SUSEMailing ListThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00003.html vendor-advisoryx_refsource_SUSEMailing ListThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00102.html vendor-advisoryx_refsource_SUSEMailing ListThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00103.html vendor-advisoryx_refsource_SUSEMailing ListThird Party Advisory
- http://packetstormsecurity.com/files/152136/Slackware-Security-Advisory-libssh2-Updates.html x_refsource_MISCPatchThird Party AdvisoryVDB Entry
- http://www.openwall.com/lists/oss-security/2019/03/18/3 mailing-listx_refsource_MLISTMailing ListPatchThird Party Advisory
- http://www.securityfocus.com/bid/107485 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2019-3859 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1687307 Issue Tracking
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3859 x_refsource_CONFIRMIssue TrackingPatchThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/03/msg00032.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/04/msg00006.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/07/msg00024.html mailing-listx_refsource_MLIST
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5DK6VO2CEUTAJFYIKWNZKEKYMYR3NO2O/ vendor-advisoryx_refsource_FEDORA
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XCWEA5ZCLKRDUK62QVVYMFWLWKOPX3LO/ vendor-advisoryx_refsource_FEDORA
- https://nvd.nist.gov/vuln/detail/CVE-2019-3859
- https://seclists.org/bugtraq/2019/Apr/25 mailing-listx_refsource_BUGTRAQMailing ListThird Party Advisory
- https://seclists.org/bugtraq/2019/Mar/25 mailing-listx_refsource_BUGTRAQMailing ListPatchThird Party Advisory
- https://security.netapp.com/advisory/ntap-20190327-0005/ x_refsource_CONFIRMThird Party Advisory
- https://www.broadcom.com/support/fibre-channel-networking/security-advisories/brocade-security-advisory-2019-767 x_refsource_CONFIRMThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2019-3859
- https://www.debian.org/security/2019/dsa-4431 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- https://www.libssh2.org/CVE-2019-3859.html x_refsource_MISCVendor Advisory
- https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html x_refsource_MISC
Change history (0)
No recorded changes yet.